In Tuḷu language the word 'aṁbu' (ಅಂಬು) means arrow. This word is used in Malayaḷam, Tamiḻ, Koḍava and Kannaḍa Languages (cognates) to mean arrow. 

Another word used in Tuḷu to mean arrow is 'pagari' (ಪಗರಿ) which was 'pagaḻi' (ಪಗೞಿ) in OldTuḷu. It is also a dravidian word. 

In Sanskrit language there is a word 'ambu' which means water. It is not related with dravidian word 'ambu' (arrow).